Re: [Qemu-devel] [PATCH] hw/i2c: Add trace events

[Corey Minyard <cminyard@mvista.com>]

On 06/06/2018 02:18 PM, Philippe Mathieu-Daudé wrote:
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
> $ qemu-system ... -d trace:i2c_recv,trace:i2c_send
>
> 4486@1528311614.709959:i2c_recv recv(addr:0x50) data:0x00
> 4486@1528311614.709994:i2c_send send(addr:0x50) data:0x05
> 4486@1528311614.710060:i2c_recv recv(addr:0x50) data:0x02
> 4486@1528311614.710161:i2c_recv recv(addr:0x50) data:0x40
> 4486@1528311614.710185:i2c_send send(addr:0x50) data:0x02
> 4486@1528311614.710233:i2c_recv recv(addr:0x50) data:0x08
> 4486@1528311614.710380:i2c_recv recv(addr:0x50) data:0x0d
> 4486@1528311614.710396:i2c_send send(addr:0x50) data:0x1f
> 4486@1528311614.710437:i2c_recv recv(addr:0x50) data:0x40
>
> or
>
> $ qemu-system ... -d trace:i2c\*
>
> 4486@1528311614.698315:i2c_event start(addr:0x50)
> 4486@1528311614.698338:i2c_recv recv(addr:0x50) data:0x82
> 4486@1528311614.698349:i2c_event finish(addr:0x50)
> 4486@1528311614.698354:i2c_event start(addr:0x50)
> 4486@1528311614.698357:i2c_send send(addr:0x50) data:0x11
> 4486@1528311614.698377:i2c_event finish(addr:0x50)
> 4486@1528311614.698380:i2c_event start(addr:0x50)
> 4486@1528311614.698402:i2c_recv recv(addr:0x50) data:0x04
> 4486@1528311614.698485:i2c_event finish(addr:0x50)

I looked this over and it all looks correct and complete.

Reviewed-by: Corey Minyard <cminyard@mvista.com>

>
>   Makefile.objs       |  1 +
>   hw/i2c/core.c       | 25 ++++++++++++++++++-------
>   hw/i2c/trace-events |  7 +++++++
>   3 files changed, 26 insertions(+), 7 deletions(-)
>   create mode 100644 hw/i2c/trace-events
>
> diff --git a/Makefile.objs b/Makefile.objs
> index 2c8cb72407..7a9828da28 100644
> --- a/Makefile.objs
> +++ b/Makefile.objs
> @@ -213,6 +213,7 @@ trace-events-subdirs += hw/char
>   trace-events-subdirs += hw/display
>   trace-events-subdirs += hw/dma
>   trace-events-subdirs += hw/hppa
> +trace-events-subdirs += hw/i2c
>   trace-events-subdirs += hw/i386
>   trace-events-subdirs += hw/i386/xen
>   trace-events-subdirs += hw/ide
> diff --git a/hw/i2c/core.c b/hw/i2c/core.c
> index ab72d5bf2b..b54725985a 100644
> --- a/hw/i2c/core.c
> +++ b/hw/i2c/core.c
> @@ -9,6 +9,7 @@
>   
>   #include "qemu/osdep.h"
>   #include "hw/i2c/i2c.h"
> +#include "trace.h"
>   
>   #define I2C_BROADCAST 0x00
>   
> @@ -130,14 +131,16 @@ int i2c_start_transfer(I2CBus *bus, uint8_t address, int recv)
>       }
>   
>       QLIST_FOREACH(node, &bus->current_devs, next) {
> +        I2CSlave *s = node->elt;
>           int rv;
>   
> -        sc = I2C_SLAVE_GET_CLASS(node->elt);
> +        sc = I2C_SLAVE_GET_CLASS(s);
>           /* If the bus is already busy, assume this is a repeated
>              start condition.  */
>   
>           if (sc->event) {
> -            rv = sc->event(node->elt, recv ? I2C_START_RECV : I2C_START_SEND);
> +            trace_i2c_event("start", s->address);
> +            rv = sc->event(s, recv ? I2C_START_RECV : I2C_START_SEND);
>               if (rv && !bus->broadcast) {
>                   if (bus_scanned) {
>                       /* First call, terminate the transfer. */
> @@ -156,9 +159,11 @@ void i2c_end_transfer(I2CBus *bus)
>       I2CNode *node, *next;
>   
>       QLIST_FOREACH_SAFE(node, &bus->current_devs, next, next) {
> -        sc = I2C_SLAVE_GET_CLASS(node->elt);
> +        I2CSlave *s = node->elt;
> +        sc = I2C_SLAVE_GET_CLASS(s);
>           if (sc->event) {
> -            sc->event(node->elt, I2C_FINISH);
> +            trace_i2c_event("finish", s->address);
> +            sc->event(s, I2C_FINISH);
>           }
>           QLIST_REMOVE(node, next);
>           g_free(node);
> @@ -169,14 +174,17 @@ void i2c_end_transfer(I2CBus *bus)
>   int i2c_send_recv(I2CBus *bus, uint8_t *data, bool send)
>   {
>       I2CSlaveClass *sc;
> +    I2CSlave *s;
>       I2CNode *node;
>       int ret = 0;
>   
>       if (send) {
>           QLIST_FOREACH(node, &bus->current_devs, next) {
> -            sc = I2C_SLAVE_GET_CLASS(node->elt);
> +            s = node->elt;
> +            sc = I2C_SLAVE_GET_CLASS(s);
>               if (sc->send) {
> -                ret = ret || sc->send(node->elt, *data);
> +                trace_i2c_send(s->address, *data);
> +                ret = ret || sc->send(s, *data);
>               } else {
>                   ret = -1;
>               }
> @@ -189,7 +197,9 @@ int i2c_send_recv(I2CBus *bus, uint8_t *data, bool send)
>   
>           sc = I2C_SLAVE_GET_CLASS(QLIST_FIRST(&bus->current_devs)->elt);
>           if (sc->recv) {
> -            ret = sc->recv(QLIST_FIRST(&bus->current_devs)->elt);
> +            s = QLIST_FIRST(&bus->current_devs)->elt;
> +            ret = sc->recv(s);
> +            trace_i2c_recv(s->address, ret);
>               if (ret < 0) {
>                   return ret;
>               } else {
> @@ -226,6 +236,7 @@ void i2c_nack(I2CBus *bus)
>       QLIST_FOREACH(node, &bus->current_devs, next) {
>           sc = I2C_SLAVE_GET_CLASS(node->elt);
>           if (sc->event) {
> +            trace_i2c_event("nack", node->elt->address);
>               sc->event(node->elt, I2C_NACK);
>           }
>       }
> diff --git a/hw/i2c/trace-events b/hw/i2c/trace-events
> new file mode 100644
> index 0000000000..d339b61202
> --- /dev/null
> +++ b/hw/i2c/trace-events
> @@ -0,0 +1,7 @@
> +# See docs/devel/tracing.txt for syntax documentation.
> +
> +# hw/i2c/core.c
> +
> +i2c_event(const char *event, uint8_t address) "%s(addr:0x%02x)"
> +i2c_send(uint8_t address, uint8_t data) "send(addr:0x%02x) data:0x%02x"
> +i2c_recv(uint8_t address, uint8_t data) "recv(addr:0x%02x) data:0x%02x"